High blood pressure is common. Left untreated, it contributes to stroke, coronary heart disease and heart failure. We therefore recommend you should get your blood pressure checked regularly. Diagnosis is quite easy and there are effective medicines to treat it.

Unfortunately, though, these can occasionally lower blood pressure too far. For younger patients, the consequence of this is that they feel faint at times, but it usually corrects quickly. Reducing the dose stops any recurrence, and this is no reason to miss out on potentially life-prolonging treatment.

But it’s not so straightforward for the elderly. They are not able to compensate so quickly for a drop in blood pressure, and the resulting unsteadiness can cause them to fall and potentially injure themselves. In addition, a critical pressure must be maintained to ensure sufficient blood flow to their brain. This is the reason it takes longer to stabilise an elderly patient on blood pressure lowering medication.

Studies show there are benefits for treating blood pressure in the elderly – but there are some nagging doubts. How do you ensure the right people are treated, especially given that there are general practice incentives in the NHS for doing so?

A recent commentary and a scientific review have raised questions about balancing the risks against the advantages of lowering blood pressure in the elderly. Dr Spence, writing in the British Medical Journal*, asks whether too many elderly patients are being put at unnecessary risk by an enthusiasm for meeting a numerical target rather than assessing all aspects of the patient. If a person is frail, ill with another condition and likely to die soon, what’s the point of ineffective treatment that carries a risk? On the other hand, someone in more robust health might benefit significantly from life-prolonging blood pressure treatment.

Many people would go along with this idea, but it’s difficult to know how to make an assessment of a patient’s frailty. It cannot simply be a matter of age. There are 80-year-olds who are active – sometimes more active than younger people – and others whose quality of life is impaired.

Recent research** has provided some help in assessing frailty through a straightforward test of walking speed. The researchers measured walking speed in 2340 patients with high blood pressure aged over 75 years. After ruling out other factors that might have interfered with walking speed, they divided the patients into those that walked faster than 0.8 meters/second (about 75 feet in 30 seconds) and those that were slower than this. Over a seven-year follow-up period, there were 24 deaths per thousand person years in the fast walkers but 70 deaths per thousand person years in the slow walkers. This suggests a way to pick out the fitter people who are more likely to benefit from life-prolonging preventive treatment.

These observations don’t fully answer every question about treating elderly people with high blood pressure and there may be other more pertinent measurements. But they do make a start in differentiating people who are frailer and therefore less likely to derive benefit from treatment.

If you are elderly and are diagnosed with high blood pressure, make sure you discuss fully all the pros and cons of treatment with your doctor before coming to an informed decision about the best option for you personally.